The breeding scheme DASHaHOUND follows is Assortative Mating (sometimes called Selective Mating). Our goal is to reduce the inbreeding coefficient in our dogs while breeding to obtain consistency in health, temperament, and conformation (in that order). Our goal is to develop two proven parallel lines which can be bred to each other (controlled outcrossing) to achieve consistency without simultaneously developing negative homozygous recessive health genes. We are willing to sacrifice some champions in our pedigrees in the short run to achieve a wider gene pool in the long run.
Our dog Whiskers vs Preston is a good example. Whiskers has 37 champions in his 5 generation Pedigree and almost no repeats. He is a great dog and is a product of Assortative Breeding. Preston has 27 in his but it is the same 5 or 6 dogs over and over. He also is a great dog and he is a product of Line Breeding. Preston’s COI (coefficient of inbreeding) is 16.33 %. Whisker’s is Zero. By finding an unrelated mate with the desired Phenols for Preston, their puppy’s COI goes to zero, even if the chosen female is the product of Line Breeding, so long as it is to a different line. We believe we can produce a champion line using this approach. Others do not think this is possible or advisable and that is OK.
In summation the risk, as we see it, are:
Outcrossing could produce an average or below average puppy or litter. It is not going to produce a puppy with two heads. It is not likely to produce an unhealthy puppy but may not necessarily produce a show dog because of conformation issues. Maybe the breeder bred a long legged dog to a short legged dog, expecting the puppies to be somewhere inbetween but instead got all long legged puppies who were too tall to show. The breeder did not acheive the desired result but those puppies would still make great pets. The puppies would be sold on spay/neuter contracts and never bred. This is commonly know as "petting out" puppies that dont't have show or breeding potential. The breeder would learn from this mating and have to try a different combination. If this is the worst result a breeder experiences it is not all that bad.
Line breeding produces more prediticable litters in the short run but runs the risk of developing heath issues over the long haul. The same process that emphasizes positve traits and makes them permanent simultaneously does the same for weaknesses. DNA analysis promises to help Line Breeders avoid the bad and emphasize the good but it is still up to the breeder to use that information. Analysis of the Whippet discovered the muscle bound "Bullies" were created by the same mutated gene that produced the fastest dogs. So instead of breeding this gene out some breeders decided to keep it. They then breed a certain percentage of Bullies to get a track fast Whippet. They destroy the Bullies as a bi product of their breeding program. This is not a program we are comfortable with and neither are any of the Dachshund breeders we know. Many breeders do believe "their genetics" don't have any weaknesses but the fact is all animals, including humans, have recessive weaknesses. Increasing these recessive tendencies is called "Inbreeding Depression" and it can take a long time to manifest itself. The long term risk is the entire line or even an entire breed can become homozygous for these weaknesses and pass them along as surely as the positive characteristics. This risk has led to the total ruin of entire kennels and even breeds in the past where there are nor clear dogs left. Note that a modern line breeder would storngly dispute this. That is why we have included some articles by people who STRONGLY believe Line Breeding is the ONLY way to breed.
We don’t claim to have a corner on all knowledge. We only make decisions for our own kennel. I am happy to say we have friends on both sides of the breeding method fence. Let each decide for himself/herself. As a practical matter most breeders are sensitive to COI. The most commoly used software is "Man's Best Friend Software" which automatically computes the COI for each dog in the pedigree and can show the COI for a proposed litter as well. We are open to all ideas and sort through them as we find our way along. What we all have in common is a love for the breed. We will see you in the show ring.
The following is a reprint of part of the Canine Diversity Project Breeding Schemes by Dr. John Armstrong.
This paragraph is selected to help explain our approach to breeding. The Magenta highlight is our planned approach. The yellow highlights are some of the reasons why:
Don't shoot the messenger: Population genetics is not really a new discipline, it just seems that way because it's generally the last chapter in a genetics text. Population geneticists are neither white knights come to save us all, nor agents of the devil intent on destroying pure breeds. Population genetics is a tool for looking at an entire population or breed. It can tell you what has happened to the genetic diversity, and whether there is any possibility of improving the situation by making appropriate crosses. How this information is used is up to the breed club and individual breeders. Though lessons may be learned from conservation biology, I do not expect breed clubs are going to be in a position to manage the entire breed. However, they may choose to limit certain practices for the overall good of the breed. The prime target, in my opinion, should be overuse of popular stud dogs.
In a managed population of an endangered species, zoo biologists might choose one of several strategies that are generally aimed at conserving the diversity from the wild population from which the captive population is drawn. This makes the assumption that all founders were equally meritorious and that their genes are all equally worthy of preservation. This is essentially a holding action and, in the absence of selection, runs the risk of creating a population that is less well adapted to returning to the wild.
In my view, the best strategy for dog breeders is carefully planned assortative mating combined with an attempt to minimize or at least reduce the inbreeding coefficient. In practice, if I am asked for an opinion on a suitable mate for a Standard Poodle, I suggest that the breeder assemble a list of dogs he/she would consider breeding to, based on conformation, temperament and whatever other criteria are deemed relevant, and I will tell them the inbreeding coefficient for each potential litter and also about the prominent ancestors in the pedigree. My personal criterion is a 10-generation COI under 10%, but I might pick one close to that, or even a bit over, if I liked the other qualities.
The COI has predictive value. I can tell you that an SP inbred to only 5% will, on average, live about 3 years longer than one bred to 35%, and I can tell you that a 10% increase will likely reduce litter size by about 7%. Both these effects are, in my opinion, most likely to result from accumulation of suboptimal alleles with small individual effects. However, inbreeding also increases the probability of doubling up on any obviously deleterious traits carried by a shared ancestor. I understand why breeders inbreed (or linebreed), but I don't agree that it is necessary to produce good dogs (see Inbreeding and Diversity). As to the claim that it can be used to uncover problems in the line, I agree, but I can also give you case histories where the breeder has proceeded to ignore a hereditary problem uncovered this way, and as a result spread it through the breed.
Neither population genetics nor modern DNA technology is going to provide magical solutions to all our problems. However, used together, they may take us through the 21st Century. Continued reliance on the models put forward in the early days of genetics almost certainly will not.
Clic the following link to read the entire article: Breeding Schemes
